The present invention relates to a retractable step system which can be built into a large vehicle such as a motorhome or retrofitted later. Although the system can be operated manually, the preferred method is to have the deployment of the steps be automatic, triggered by the opening and closing of the driver's door. The design of the retractable steps provides a place for the driver to step which extends far enough beyond the body of the vehicle to allow the driver to bring his/her full weight directly over the step before moving to the next step or into the vehicle. The specific design of the device provides for control of the rate of movement and the force behind each movement to avoid injury to anyone or anything in the path of the subject movement. It also provides for a positive locking of each step in place to provide secure footing for any person using it.
The need for the subject invention comes from the fact that, in many large vehicles such as a Class A motorhome the floor in the driver's area is often 3½ feet or more above the ground. Also in many of these large vehicles the driver sits nearly over the front wheel. It is impractical to employ a retractable step of the type commonly used in the middle of the passenger side on many Class A motorhomes, since it would have to be installed where the front wheel is located. The present invention, due to its rotary action, can rotate out from either in front of or behind the front wheel to provide a step or steps where needed. Some attempts have been made to solve this problem by building in a set of fixed steps for the driver similar to the classic bus entrance steps. However, this has proven difficult due to the presence of both the front wheel and the driver's controls. As a result, those manufacturers who provide a driver's side door on Class A motorhomes, do so as a “safety” measure, not as a convenient way into and out of the vehicle. However, even as an “emergency” exit these doors are not really safe for use by any but the most athletic person.
Typically manufacturers of “Class A” motorhomes equipped with driver's side doors have provided various types of pocket steps built into the side of the motorhome or various types of stirrup steps mounted in the wheel well area. Coupled with these are various grab bars and hand grips. However, considerable athletic ability is needed to get in and out of the vehicle using these devices. The main problem with these steps and/or stirrups is that a person attempting to go into or out of the vehicle using them must depend on arm strength to support much of the person's weight. Many people using motorhomes are not capable of doing this easily and safely. The present invention eliminates most or all of this requirement for arm strength. Also, the previous types of step devices are often hard to locate with a foot and are very easy to miss when the person is exiting the vehicle. This has resulted in injuries. The present invention solves this problem because the step or steps are clearly visible and readily accessible to the person exiting the vehicle.
Prior art includes a large variety of stirrups, pocket steps, grab handles and grab bars both inside and outside various vehicles, including motorhomes. For example, U.S. Pat. Nos. 6,179,312 (Paschke et al.) and 6,264,222 (Johnston et al.), both of which use a vertical pivot but are not shaft mounted. They both require major body design modifications and are therefore not suitable for retrofit to existing vehicles. The present invention is readily adaptable to retrofit to existing vehicles and vehicle design. These two patented devices are also designed primarily for use on truck cabs rather than motorhomes.
A number of other existing patents utilize a rotary motion to extend and retract a step from beneath the body of a vehicle. For example, U.S. Pat. Nos. 4,231,583 (Learn), 3,980,319 (Kirkpatrick), 4,708,355 (Tiede) and 3,762,742 (Bucklen), teach a step rotating on an inclined axis to place the step low to the ground when extended and clear the body lower edge when retracted. This limits the size of the step to not much more than a stirrup. An important aspect of the present invention is the large size of the step or steps which allows the person using them to have their weight fully centered over each step. Tiede also uses electric motor actuation rather than the air cylinder actuation employed in the present invention. Yet another rotary step patent (U.S. Pat. No. 5,897,125, Bundy) is a small treadle manually deployed to provide access at the side of a pick up truck bed.
Other patents which employ the concept of a step rotating out from under the vehicle body about a vertical axis are U.S. Pat. Nos. 3,329,443 (Lowder et al.), 6,283,537 (DeVore), 6,659,484 (Knodle et al.) and 3,861,713 (McKee), all teach a rotational step which retracts beneath the vehicle body but none of them apply to the driver's side door as does the present invention. Additionally, U.S. Pat. No. 3,388,925 (Chavira et al.) teaches a vertical shaft mounted step assembly to provide access to a loading dock and therefore differs from the present invention which provides access to and from the driver's side door.
The following list of prior patents presents a variety of step mechanisms which do not meet the requirements for an automatically deployed step assembly providing comfortable access to and from the driver's side door of a large motorhome for people of limited athletic ability as the present invention does. U.S. Pat. Nos. 6,942,233 (Leitner et al.), 6,655,706 (Murrell), 5,687,813 (Bensch), 5,660,405 (Campbell), 5,456,479 (Conger), 5,342,073 (Poole), 5,284,349 (Bruns et al.), 5,224,723 (Hatas), 5,195,609 (Ham et al.), 5,150,659 (Bickel), 5,137,294 (Martin), 5,092,617 (Jones), 4,264,084 (Telles), 4,251,179 (Thorley), 4,217,971 (Rivinius), 4,200,303 (Kelly), 4,185,849 (Jaeger), 4,106,790 (Weiler), 3,912,298 (Humphrey), 3,833,240 (Weiler), 3,807,758 (Rogge), 3,756,622 (Pyle et al.), 3,743,320 (Clark) and 3,751,068 (Green).